131,237 research outputs found
Stochastic synaptic plasticity in deterministic aVLSI networks of spiking neurons
No full textChicca E, Fusi S. Stochastic synaptic plasticity in deterministic aVLSI networks of spiking neurons. In: Rattay F, ed. Proceedings of the World Congress on Neuroinformatics. Vienna: ARGESIM/ASIM Verlag; 2001: 468-477.Stochastic learning solves the stability-plasticity problem (Fusi et al., 2000a)
but raises new issues related to the generation of the proper noise driving
the synaptic dynamics. Here we show that a simple, fully deterministic,
spike-driven synaptic device can make use of the network generated vari-
ability in the neuronal activity to drive the required stochastic mechanism.
Randomness emerges naturally from the interaction of deterministic neu-
rons, and no extra source of noise is needed. Learning and forgetting
rates of the network can be easily controlled by changing the statistics of
the spike trains without changing any inherent parameter of the synaptic
dynamics
Ample vector bundles with small
No full textLet X be a smooth complex projective variety and let Z be a smooth submanifold of X of dimension ge 2, which is the zero locus of a section of an ample vector bundle E of rank dim X - dim Z ge 2. Let H be an ample line bundle on X, whose restriction H_Z to Z is generated by global sections. The structure of triplets (X,E,H) as above is described under the assumption that the curve genus of the corank-1 vector bundle E oplus H^{oplus (dim Z -1)} is le q+2, where q is the irregularity of X
Proprietà reologiche dei fusi naturali: i liquidi magmatici
No full textRiassunto: Questo contributo fornisce un aggiornamento sui più recenti studi
sperimentali e sui modelli di calcolo relativi allo studio della reologia dei fusi silicatici naturali
Construction of linear pencils of cubic curves with Mordell-Weil rank six and seven
No full textP(論文)departmental bulletin pape
PENGARUH LAMA WAKTU INKUBASI TERHADAP FUSI PROTOPLAS MESOFIL DAUN ANGGREK Dendrobium sylvanum Rchb.f dan Dendrobium lasianthera J.J.Sm
No full textPenelitian ini bertujuan untuk mengetahui pengaruh lama waktu inkubasi pada isolasi dan fusi protoplas Dendrobium sylvanum Rchb.f and Dendrobium lasianthera J.J.Sm serta pengaruh jenis tanaman terhadap hasil isolasi protoplas. Penelitian ini terdiri atas dua tahap yaitu isolasi dan fusi protoplas. Kedua tahap tersebut merupakan penelitian eksperimental dengan Rancangan Acak Lengkap (RAL). Metode isolasi protoplas menggunakan enzim cellulase Onozuka R-10 1%, macerozyme R-10 0,2%, dan larutan stabilisator sukrosa 0,5 M untuk merendam 2 gram eksplan selama 1, 3, 5, 7 jam dengan enam kali ulangan. Eksplan diambil dari jaringan mesofil dalam kondisi in vitro. Pada tahap dua, fusi protoplas dilakukan secara kimiawi menggunakan PEG 6000 30%. Fusi dilakukan selama 20, 30, 40, dan 50 menit dengan enam kali ulangan untuk melihat pengaruh lama waktu inkubasi terhadap hasil fusi. Hasil isolasi protoplas diuji menggunakan One Way Anova dilanjutkan dengan Duncan Multiple Range Test (DMRT) sedangkan jenis tanaman dan fusi protoplas diuji dengan Kruskal Wallis dilanjutkan dengan uji Mann Whitney. Pada isolasi protoplas, lama waktu inkubasi selama 3 jam dalam larutan enzim dan stabilisator sukrosa masing-masing memberikan jumlah protoplas viabel paling optimum. Jumlah protoplas viabel pada D. lasianthera adalah 15,6x105 protoplas/ mL, sedangkan D. sylvanum adalah 6,6x105 protoplas/ mL. Waktu inkubasi selama 40 menit memberikan hasil fusi paling baik yaitu 6,4% pada homofusi D. lasianthera, 6,6% homofusi D. sylvanum, dan 7,4% pada heterofusi sedangkan untuk multifusi mencapai 18,3%. Hasil penelitian menunjukkan jenis tanaman dan perlakuan lama waktu inkubasi berpengaruh terhadap hasil isolasi dan fusi protoplas.
Kata kunci: isolasi protoplas, Dendrobium sylvanum, Dendrobium lasianthera
Photocycloadditions on 2-Methyloxazolo[5,4-b]pyridine
No full textThe title compound undergoes photocycloadditions with both electron-poor alkenes (methacrylonitrile) and electron-rich alkenes (ethyl vinyl ether and furan). The initial photoadducts evolve into a variety of compounds. In the photoreaction with methacrylonitrile, oxazoloazocines 5 and 7 and cyclopentenylidenes 6Z and 6E are obtained; the photoadducts with vinyl ether yield oxazoloazocines 9 and 11, substituted oxazoles 10 and 12, and pyrrolopyridine 13; from the reaction with furan the furylpyridine 14 was isolated. ((C) Wiley-VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2002)
5-Amino-8-(1-aminoethylidene)-8H-tetrazolo[1,5-a]pyridin-7-one dihydrate
No full textThe title compound, C7H8N6O·2H 2O, contains a tetrazole ring fused to a substituted pyridone ring. Bond lengths correspond to delocalized π electrons in the tetrazole moiety and a push-pull effect in the pyridone ring. An extended network of hydrogen bonds connects the molecules in planes parallel to the be plane, while the water molecules form chains parallel to the a axis. © 2003 International Union of Crystallography Printed in Great Britain - all rights reserved
Photochemistry of 4,6-Diazido-3-methylisoxazolo[4,5-c]pyridines: a convenient entry to 3-Methylisoxazolo[1,3]diazepine system
No full textUV irradiation of 4,6-diazido-3-methylisoxazolo[4,5-c] pyridine in methanol gives the 3-methylisoxazolo-1,3-diazepine derivatives 3,4 by nitrogen loss and solvent addition
MAXIMAL OXYGEN CONSUMPTION AND ENERGY COST OF RUNNING AFTER A LONG-LASTING RACE: THE 100 KM OF SAHARA
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